Boil liver and parboil the onion, then mince them together. Lightly brown the oatmeal. Mix all ingredients together. Fill the sheep’s pluck with the mixture pressing it down to remove all the air, and sew up securely. Prick the haggis in several places so that it does not burst. Place haggis in boiling water and boil slowly for 4-5 hours. Serves approximately 12.